Schistosomiasis

A comprehensive exploration of schistosomiasis: Global impact, molecular characterization, drug discovery, artificial intelligence and future prospects

Schistosomiasis, one of the neglected tropical diseases which affects both humans and animals, is caused by trematode worms of the genus Schistosoma. The disease is caused by several species of Schistosoma which affect several organs such as urethra, liver, bladder, intestines, skin and bile ducts. The life cycle of the disease involves an intermediate host (snail) and a mammalian host. It affects people who are in close proximity to water bodies where the intermediate host is abundant. Common clinical manifestations of the disease at various stages include fever, chills, headache, cough, dysuria, hyperplasia and hydronephrosis. To date, most of the control strategies are dependent on effective diagnosis, chemotherapy and public health education on the biology of the vectors and parasites. Microscopy (Kato-Katz) is considered the golden standard for the detection of the parasite, while praziquantel is the drug of choice for the mass treatment of the disease since no vaccines have yet been developed. Most of the previous reviews on schistosomiasis have concentrated on epidemiology, life cycle, diagnosis, control and treatment. Thus, a comprehensive review that is in tune with modern developments is needed. Here, we extend this domain to cover historical perspectives, global impact, symptoms and detection, biochemical and molecular characterization, gene therapy, current drugs and vaccine status. We also discuss the prospects of using plants as potential and alternative sources of novel anti-schistosomal agents. Furthermore, we highlight advanced molecular techniques, imaging and artificial intelligence that may be useful in the future detection and treatment of the disease. Overall, the proper detection of schistosomiasis using state-of-the-art tools and techniques, as well as development of vaccines or new anti-schistosomal drugs may aid in the elimination of the disease.

Dichroa febrifuga Lour.: A review of its botany, traditional use, phytochemistry, pharmacological activities, toxicology, and progress in reducing toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Dichroa febrifuga Lour., a toxic but extensively used traditional Chinese medicine with a remarkable effect, is commonly called "Changshan" in China. It has been used to treat malaria and many other parasitic diseases.

AIM OF THE REVIEW

The study aims to provide a current overview of the progress in the research on traditional use, phytochemistry, pharmacological activities, toxicology, and methods of toxicity reduction of D. febrifuga. Additionally, further research directions and development prospects for the plant were put forward.

MATERIALS AND METHODS

The article uses "Dichroa febrifuga Lour." "D. febrifuga" as the keyword and all relevant information on D. febrifuga was collected from electronic searches (Elsevier, PubMed, ACS, CNKI, Google Scholar, and Baidu Scholar), doctoral and master's dissertations and classic books about Chinese herbs.

RESULTS

30 chemical compounds, including alkaloids, terpenoids, flavonoids and other kinds, were isolated and identified from D. febrifuga. Modern pharmacological studies have shown that these components have a variety of pharmacological activities, including anti-malarial activities, anti-inflammatory activities, anti-tumor activities, anti-parasitic activities and anti-oomycete activities. Meanwhile, alkaloids, as the material basis of its efficacy, are also the source of its toxicity. It can cause multiple organ damage, including liver, kidney and heart, and cause adverse reactions such as nausea and vomiting, abdominal pain and diarrhea. In the current study, the toxicity can be reduced by modifying the structure of the compound, processing and changing the dosage forms.

CONCLUSIONS

There are few studies on the chemical constituents of D. febrifuga, so the components and their structure characterization contained in it can become the focus of future research. In view of the toxicity of D. febrifuga, there are many methods to reduce it, but the safety and rationality of these methods need further study.

Capacities and needs of health care facilities for schistosomiasis diagnosis and management in elimination settings

BACKGROUND

Schistosomiasis is a debilitating neglected tropical disease endemic in sub-Saharan Africa. The role of health facilities in the prevention, diagnosis, control, and elimination of schistosomiasis is poorly documented. In a setting targeted for schistosomiasis elimination in Zanzibar, we assessed the prevalence of Schistosoma haematobium among patients seeking care in a health facility and investigated schistosomiasis-related knowledge of staff, and health facilities' capacities and needs for schistosomiasis diagnosis and management.

METHODS

We conducted a health facility-based mixed-method study on Pemba Island from June to August 2023. Patients aged ≥ 4 years seeking care in four health facilities were screened for S. haematobium infection using urine filtration and reagent strips. Those patients aged ≥ 10 years were additionally interviewed about signs and symptoms. Staff from 23 health facilities responded to a questionnaire assessing knowledge and practices. Ten staff participated in a focus group discussion (FGD) about capacities and needs for schistosomiasis diagnosis and management.

RESULTS

The prevalence of S. haematobium infection in patients attending the health facilities, as determined by the presence of eggs in urine, was 1.1% (8/712). Microhaematuria was detected in 13.3% (95/712) of the patients using reagent strips. Among patients responding to the questionnaire, pelvic pain, pain during sex, and painful urination were reported by 38.0% (237/623), 6.3% (39/623), and 3.2% (20/623), respectively. Among the health facility staff, 90.0% (44/49) and 87.8% (43/49) identified blood in urine and pelvic pain, respectively, as symptoms of urogenital schistosomiasis, 81.6% (40/49) and 93.9% (46/49) reported collecting a urine sample and pursuing a reagent strip test, respectively, for diagnosis, and 87.8% (43/49) administered praziquantel for treatment. The most reoccurring themes in the FGD were the need for more staff training about schistosomiasis, requests for diagnostic equipment, and the need to improve community response to schistosomiasis services in health facilities.

CONCLUSIONS

The prevalence of S. haematobium infection in patients seeking care in health facilities in Pemba is very low and similar to what has been reported from recent community-based cross-sectional surveys. The health facility staff had good schistosomiasis-related knowledge and practices. However, to integrate schistosomiasis patient management more durably into routine health facility activities, scalable screening pathways need to be identified and capacities need to be improved by regular staff training, and an unbroken supply of accurate point-of-care diagnostics and praziquantel for the treatment of cases.

Immunochromatographic POC-CCA Test for the diagnosis of intestinal schistosomiasis in a high endemic region in Brazil: Differences in the interpretation of results

The POC-CCA test is subject to variations in reading interpretations depending on the intensity of its results, and trace test reading have implications for determining prevalence. The aim of this study was to assess whether the readings obtained from the POC-CCA tests, conducted using a semi-quantitative scale (the G-score classification for test determination), exhibited concurrence with the direct visual interpretation (positive, negative, or trace) performed by two distinct analysts, using photographs from previously performed POC-CCA test carried out in the municipality of Maruim, in the state of Sergipe-Brazil, a region of high endemicity. The devices used to read the photographs were smartphones, so as to simulate field usage, and a desktop, a tool with higher image quality that would help the researchers in the evaluation and establishment of the final result at a later. In direct visual interpretation of the POC-CCA photographs, the most discordant results occurred in the identification of the trace response (T). The Kappa index established for the direct visual interpretation between the two analysts, in which T is considered as positive, in the desktop was κ=0.826 and in the smartphone, κ=0.950. When we use the G-score as a reading standardization technique and classify the results according to the manufacturer, with trace being evaluated as positive, the highest level of agreement was obtained. Some disagreement remains between the direct visual interpretation and the G-score when performed on the desktop, with more individuals being classified as negative in the direct visual interpretation, by both analysts. However, this result was not statistically significant. The use of the G-score scale proved to be an excellent tool for standardizing the readings and classifying the results according to the semi-quantitative scale showed greater concordance of results both among analysts and among the different devices used to view the photographs.

Prevalence of depressive symptoms in patients with advanced schistosomiasis in China: A systematic review and meta-analysis

BACKGROUND

Advanced schistosomiasis is the most serious outcome of infection and has a negative impact on both physical fitness and mental health of patients, the latter of which has long been overlooked. Therefore, we performed this systematic review and meta-analysis to estimate the overall prevalence of depressive symptoms, one of the most common mental problems, in patients with advanced schistosomiasis in China.

METHODS

Six electronic databases were searched for studies reporting the prevalence of depressive symptoms in the targeted patients. Assessments were pooled using a fixed- or random-effects model based on heterogeneity test. Subgroup analyses were further performed and differences between/among groups were examined using the chi-squared test. The protocol had previously been registered in PROSPERO (CRD42023406708).

RESULTS

A total of 11 studies with 1,673 participants were included. The pooled prevalence of depressive symptoms in advanced schistosomiasis in China was 62.01% (95% CI: 51.30% - 72.72%), with a significant heterogeneity among studies. Depressive symptoms were more prevalent in patients with complications and more than half of the patients suffered a mild- or moderate-level of depression. No publication bias was found, and sensitivity analysis showed a stable result.

CONCLUSIONS

The overall prevalence of depressive symptoms in advanced schistosomiasis in China was high enough to warrant psychotherapeutic interventions, especially for patients with complications. This would greatly prevent or/and reduce depression and improve their quality of life.

Outcome of cataract surgery in children with presumed trematode-induced granulomatous anterior uveitis

PURPOSE

To examine the 6-month visual outcomes and complications following cataract surgery in patients with persumed trematode induced granulomatous anterior uveitis.

SETTING

Assiut university hospital, Assiut, Egypt.

DESIGN

This is a retrospective non comparative case series study.

METHODS

Patients presenting with significant cataract secondary to uveitis caused by trematode induced anterior chamber granuloma were included in this study. Cases with active anterior uveitis, within the last 3 months preceding surgery, and those with a history of trauma, were excluded from this study. Data collected included demographic characteristics, history of the condition including when uveitis started, treatment received and history of other health conditions that may be relevant to uveitis.Complete opthalmologic examination including assessment of best corrected visual acuity (BCVA) and OCT macula, if possible, were done. These was repeated 1 week, 1 month, 3 months and 6 months after surgery. Specular microscopy was performed preoperatively and 3 months after surgery. Patients underwent cataract surgery with posterior chamber intra ocular lens and statistical analysis was performed to compare preoperative and postoperative BCVA and corneal endothelial cell counts. Postoperative complications were recorded.

RESULTS

Five eyes of 5 patients were included in the study. All study eyes showed improvement in the post-operative visual acuity. A statistically significant improvement was observed in VA in the sixth postoperative month compared to the baseline measurements (p = 0.004). No statistically significant difference was observed between the preoperative and postoperative endothelial cell counts (p = 0.696). Cystoid macular edema did not occur as a postoperative complication.

CONCLUSION

Visual outcomes of cataract surgery in eyes with persumed trematode induced granulametous anterior uveitis are favorable. No sight threatening complication was observed in our series.

Development and evaluation of the in vitro schistosomicidal activity of solid dispersions based on 2-(-5-bromo-1-H-indole-3-yl-methylene)-N-(naphthalene-1-ylhydrazine-carbothiamide

Among all the neglected diseases, schistosomiasis is considered the second most important parasitic infection after malaria. Praziquantel is the most widely used drug for this disease, but its exclusive use may result in the development of drug-resistant schistosomiasis. To increase the control of the disease, new drugs have been developed as alternative treatments, among them 2-(-5-bromo-1-h-indole-3-yl-methylene)-N-(naphthalene-1-ylhydrazine-carbothiamide (LQIT/LT-50), which showed promising schistosomicidal activity in nonclinical studies. However, LQIT/LT-50 presents low solubility in water, resulting in reduced bioavailability. To overcome this solubility problem, the present study aimed to develop LQIT/LT-50 solid dispersions for the treatment of schistosomiasis. Solid dispersions were prepared through the solvent method using Soluplus©, polyethylene glycol (PEG) or polyvinylpyrrolidone (PVP K-30) as hydrophilic carriers. The formulations with the best results in the compatibility tests, aqueous solubility and preliminary stability studies have undergone solubility tests and physicochemical characterizations by Fourier-transform infrared spectroscopy (FTIR), x-ray diffractometry (XRD), exploratory differential calorimetry (DSC), thermogravimetry (TG) and Raman spectroscopy. Finally, the schistosomicidal activity was evaluated in vitro. The phycochemical analyzes showed that when using PVP K-30, there was an interaction between the PVP K-30 and LQIT/LT-50, proving the successful development of the solid dispersion. Furthermore, an increase in the solubility of the new system was observed (LQIT/LT-50:PVP K-30) in addition to the improvement in the in vitro shistosomidal activity at 1:4 (w/w) molar ratio (i.e., 20% drug loading) when compared to LQIT/LT-50 alone. The development of the LQIT/LT-50:PVP K-30 1:4 solid dispersion is encouraging for the future development of new pharmaceutical solid formulations, aiming the schistosomicidal treatment.

A Mini-Review on Elisa-Based Diagnosis of Schistosomiasis

BACKGROUND

Schistosomiasis is a neglected tropical parasitic disease caused by trematode worms of the genus schistosoma, which affects approximately 240 million people worldwide. the diagnosis of the disease can be performed by parasitological, molecular, and/or immunological methods, however, the development of new diagnostic methods still essential to guide policy decisions, monitor disease trends and assess the effectiveness of interventions.

OBJECTIVE

in this sense, the current work summarizes the findings of a systematic review regarding antigens applied in the enzyme-linked immunosorbent assay test, which were patented and published over the last ten years.

METHODS

the literature search strategy used medical subject heading (mesh) terms to define as descriptors. "schistosoma mansoni" was used in arrangement with the descriptors "immunoassay", "enzyme-linked immunosorbent assay", "elisa", and "antigens", using the "and" connector. the patent search was done using keywords, including diagnosis and schistosoma or schistosomiasis or schistosome. several databases were employed for the patent search, such as intellectual property national institute; european patent office; the united states patent and trademark office; patent scope, and google patents.

RESULTS

forty-one articles were retrieved, of which only five met the eligibility criteria. seventeen patents were taken from the databases, and a brief description of the most relevant inventions is given here.

CONCLUSION

schistosomiasis is considered the most important helminthic disease in worldwide. therefore, it is important to of searching for and develops diagnostic methods based on serology to reduce morbidity and mortality caused by the disease.

Schistosoma japonicum Associated Colorectal Cancer and Its Management

BACKGROUND

An association between Schistosoma japonicum and colorectal cancer in humans has been known since a long time; however, this association remains understudied and lacks comprehensive experimentation support.

OBJECTIVE

Various epidemiological and pathological studies have established the role of chronic inflammation as a major factor behind the induction of colorectal cancer. The aim of this review is to present the current knowledge on the association of Schistosoma japonicum with colorectal cancer.

RESULT

Mechanisms which lead to induction and progression of colorectal cancer are highlighted along with diagnosis and treatment for the same. Further, various methodologies, including mass drug administration, use of new drugs and vaccines, role of apoptosis, and histone-modifying enzymes, have been described which can either prevent the schistosomal infection itself or can check it from reaching an advanced stage.

CONCLUSIONS

Epidemiological, clinical, pathological and surgical studies suggest that Schistosoma japonicum is responsible for induction of colorectal cancer. However, thorough clinical studies are required to support and globally accept this notion. Further, methodologies highlighted in this work can be employed in order to take care of schistosomal infection or address the cancer induction and progression.

Cloning, characterization, and inhibition of the novel β-carbonic anhydrase from parasitic blood fluke, Schistosoma mansoni

Schistosoma mansoni is an intestinal parasite with one β-class carbonic anhydrase, SmaBCA. We report the sequence enhancing, production, catalytic activity, and inhibition results of the recombinant SmaBCA. It showed significant catalytic activity on CO₂ hydration in vitro with k_cat 1.38 × 10⁵ s^-1 and k_cat/K_m 2.33 × 10⁷ M^-1 s^-1. Several sulphonamide inhibitors, from which many are clinically used, showed submicromolar or nanomolar inhibitory effects on SmaBCA. The most efficient inhibitor with a K_I of 43.8 nM was 4-(2-amino-pyrimidine-4-yl)-benzenesulfonamide. Other effective inhibitors with K_Is in the range of 79.4-95.9 nM were benzolamide, brinzolamide, topiramate, dorzolamide, saccharin, epacadostat, celecoxib, and famotidine. The other tested compounds showed at least micromolar range inhibition against SmaBCA. Our results introduce SmaBCA as a novel target for drug development against schistosomiasis, a highly prevalent parasitic disease.

Schistosoma Infection Burden and Risk Factors among School-Aged Children in a Rural Area of the Democratic Republic of the Congo

Despite continuous efforts to control schistosomiasis (SCH) in the Democratic Republic of the Congo (DRC), it still poses a significant challenge. In order to enhance control measures, additional research is necessary. This study documents the burden of SCH infection and its predictors in a rural area of the DRC. We conducted a household cross-sectional study from June to August 2021 among 480 school-aged children (SAC) aged 5-15 years living in a rural area of Kisangi, in the southwest DRC. We collected and examined stool, urine, and blood samples of each child. Additionally, we obtained data on anthropometry, socio-demographics, household information, and individual water contact behaviors. The overall prevalence of SCH infection was 55.8% (95% CI: 51.4-60.3), with prevalences of 41% (95% CI: 36.6-45.5), 36.3% (95% CI: 31.9-40.6), and 38.4% (95% CI: 32.6-44.3) for S. haematobium and S. mansoni infections and both infections, respectively. Among those with SCH infection, most had a light (67.5%) or heavy (51.7%) infection intensity. The geometric mean egg count was 16.6 EP 10 mL (95% CI: 12.9-21.3) for S. haematobium and 390.2 EPG (95% CI: 300.2-507.3) for S. mansoni. However, age (10 years and above (aOR: 2.1; 95% CI: 1.5-3.1; p < 0.001)) was an independent risk factor for SCH infection. The overall prevalence of malaria infection was 16.9% (95% CI: 13.5-20.2), that of stunting was 28.7% (95% CI: 24.7-32.8), that of underweight was 17.1% (95% CI: 12.8-21.4), and that of thinness was 7.1% (95% CI: 4.8-9.4). Anemia was prevalent at 49.4% (95% CI: 44.9-5), and the median Hb level of all participants was 11.6 g/dL (IQR: 10.5-12.6 g/dL). Anemia was strongly associated with SCH infection (aOR: 3.4; 95% CI: 2.3-5.1; p < 0.001) yet there was no association with the risk for malaria infection (aOR: 1.0; 95% CI: 0.6-1.8; p = 0.563). In addition, the risk of anemia increased with heavy infection intensities (p < 0.026 and p < 0.013 for S. haematobium and S. mansoni, respectively). However, stunting had a protective factor for anemia (aOR: 0.3; 95% CI: 0.2-0.4; p < 0.001). To conclude, SCH infection was widespread among the SAC and strongly linked to anemia. These results provide evidence of the hyperendemicity of infection in the study area, which requires preventative measures such as chemotherapy to reduce the schistosomiasis-associated morbidity, and micronutrient supplements to avoid anemia.

Schistosoma and Leishmania: An Untold Story of Coinfection

A remarkable characteristic of infectious diseases classified as Neglected Tropical Diseases (NTDs) is the fact that they are mostly transmitted in tropical and subtropical regions with poor conditions of sanitation and low access to healthcare, which makes transmission areas more likely to overlap. Two of the most important NTDs, schistosomiasis and leishmaniasis, despite being caused by very different etiological agents, have their pathogenesis heavily associated with immune-mediated mechanisms, and Schistosoma spp. and Leishmania spp. have been shown to simultaneously infect humans. Still, the consequences of Schistosoma-Leishmania coinfections remain underexplored. As the inflammatory processes elicited by each one of these parasites can influence the other, several changes have been observed due to this coinfection in naturally infected humans, experimental models, and in vitro cell assays, including modifications in susceptibility to infection, pathogenesis, prognostic, and response to treatment. Herein, we review the current knowledge in Schistosoma-Leishmania coinfections in both human populations and experimental models, with special regard to how schistosomiasis affects tegumentary leishmaniasis, discuss future perspectives, and suggest a few steps to further improve our understanding in this model of parasite-host-parasite interaction.

Establishing a single-sex controlled human Schistosoma mansoni infection model for Uganda: protocol for safety and dose-finding trial

Control of schistosomiasis depends on a single drug, praziquantel, with variable cure rates, high reinfection rates, and risk of drug resistance. A vaccine could transform schistosomiasis control. Preclinical data show that vaccine development is possible, but conventional vaccine efficacy trials require high incidence, long-term follow-up, and large sample size. Controlled human infection studies (CHI) can provide early efficacy data, allowing the selection of optimal candidates for further trials. A Schistosoma CHI has been established in the Netherlands but responses to infection and vaccines differ in target populations in endemic countries. We aim to develop a CHI for Schistosoma mansoni in Uganda to test candidate vaccines in an endemic setting. This is an open-label, dose-escalation trial in two populations: minimal, or intense, prior Schistosoma exposure. In each population, participants will be enrolled in sequential dose-escalating groups. Initially, three volunteers will be exposed to 10 cercariae. If all show infection, seven more will be exposed to the same dose. If not, three volunteers in subsequent groups will be exposed to higher doses (20 or 30 cercariae) following the same algorithm, until all 10 volunteers receiving a particular dose become infected, at which point the study will be stopped for that population. Volunteers will be followed weekly after infection until CAA positivity or to 12 weeks. Once positive, they will be treated with praziquantel and followed for one year. The trial registry number is ISRCTN14033813 and all approvals have been obtained. The trial will be subjected to monitoring, inspection, and/or audits.

Advances in Diagnosis of Schistosomiasis: Focus on Challenges and Future Approaches

Schistosomiasis is the second most devastating parasite prevalent in the tropical region of the world, posing significant public health impacts in endemic areas. Presently, several disease mitigation measures have shown a decline in transmission of the infection rate in risk localities using mass drug administration (MDA) of school-based or community-wide treatments. Despite all the endeavors made, the decline in transmission of infection rate has not been attained in the entire medicated segment of the population. Perhaps the current challenges of control of the disease appear to be strongly associated with a lack of appropriate diagnostic tools. It's well known that the current diagnosis of schistosomiasis greatly relies on conventional methods. On the other hand, minor symptoms of schistosomiasis and low sensitivity and specificity of diagnostic methods are still unresolved diagnostic challenges to clinicians. Numerous scholars have reviewed various diagnostic methods of schistosomiasis and attempted to identify their strengths and weaknesses, currently on function. As a result of the known limitations of the existing diagnostic tools, the need to develop new and feasible diagnostic methods and diagnostic markers is unquestionable for more precise detection of the infection. Hence, advances in diagnostic methods have been considered part of the solution for the control and eventual elimination strategy of the disease in endemic areas. As of today, easy, cheap, and accurate diagnostics for schistosomiasis are difficult to get, and this limits the concerted efforts towards full control of schistosomiasis. While looking for new diagnostic methods and markers, it is important to simultaneously work on improving the existing diagnostic methods for better results. This review tries to give new insights to the status of the existing diagnostic methods of schistosomiasis from conventional to modern via summarizing the strengths and limitations of the methods. It also tries to recommend new, sensitive and feasible diagnostic methods for future approaches.

SjHSP90 recombinant protein and its possible application in the diagnosis of schistosomiasis and treatment efficacy monitoring

PURPOSE

The fraction antigen of Schistosoma japonicum (107-121 kDa) eggs can be used for treatment efficacy monitoring, but the methods are laborious. This study analyzed the antigen and its feasibility for infection screening and treatment efficacy monitoring, which is the key to schistosomiasis control.

METHODS

The fraction antigens have been analyzed by shotgun mass spectrometry. The recombinant proteins of candidates from the fraction antigens have been prokaryotic expression and purification in large amounts with high purity. The sera have been collected from rabbits and mice models of schistosomiasis infection and treatment. ELISA evaluated the diagnostic value of the candidate proteins.

RESULTS

SJCHGC00820 and SJCHGC06900, with higher credibility, were identified through Shotgun mass spectrometry. ELISA results showed that rSj00820 has a diagnostic value for schistosomiasis (positive OD/negative OD P/N=3.6), while rSj06900 showed negative (P/N)<2. In rabbits, the specific serum antibodies for SjHSP90(rSj00820) in the infected animals peaked 6 weeks after infection and gradually decreased after treatment, reaching negative levels at 11 weeks. SjHSP90-ELISA was used to test serum samples from infected mice. The sensitivity and specificity reached >90%, similar to the diagnostic value obtained with soluble egg antigen (SEA) (SEA-ELISA). After treatment, the negative conversion rate reached >80%, significantly superior to SEA-ELISA.

CONCLUSIONS

The SjHSP90-ELISA can be used for the immunological diagnosis and treatment efficacy monitoring of schistosomiasis. The study lays a foundation for further developing screening and diagnostic kits.

Comparison of the prognostic value of stromal tumor-infiltrating lymphocytes and CD3 + T cells between schistosomal and non-schistosomal colorectal cancer

AIM

To compare the prognostic value of tumor-infiltrating lymphocytes (TILs) and CD3 + cells and CD20 + cells between schistosomal colorectal cancer (SCRC) and non-schistosomal CRC (NSCRC).

BACKGROUND

Although schistosomiasis has been basically eliminated, it has not been completely extinction in China, and occasional outbreaks occur in Europe recently. The role of immune cells in the immune microenvironment of SCRC and NSCRC is remaining obscure, and the inflammation-based prognostic systems of SCRC has rarely been reported.

METHODS

HE-stained sections of 349 colorectal cancer (CRC) tumors, which were completely resected, were evaluated for density of TILs. Meanwhile, we evaluated CD3 + T lymphocytes and CD20 + B lymphocytes by immunochemistry. The relationship of these infiltrating immune cells with clinicopathological features, including schistosomiasis, and clinical outcomes was evaluated, and the prognostic roles of TILs in SCRC and NSCRC were explored.

RESULTS

Except for age (P < 0.0001), there were no significant differences between NSCRC and SCRC patients in clinicopathological features (P > 0.05). Beside, the positive expression pattern of sTILs, iTILs, CD3, and CD20 between NSCRC and SCRC patients was also similar (P > 0.05). In the whole cohort, sTILs and CD3 were defined as independent prognostic factors (P = 0.031 and P = 0.003, respectively). CD3 was an independent prognostic factor both in the NSCRC and SCRC set (P = 0.026 and P = 0.045, respectively). Higher sTILs, CD3, and CD20 were correlated with less aggressive tumor characteristics in the whole cohort and in subgroups.

CONCLUSION

Although CD3 was an independent prognostic factor for both NSCRC and SCRC set, there were no significant differences between SCRC and NSCRC patients in sTILs, CD3, CD20, and in other clinicopathological features.

Development of a Duplex LAMP Assay with Probe-Based Readout for Simultaneous Real-Time Detection of Schistosoma mansoni and Strongyloides spp. -A Laboratory Approach to Point-Of-Care

Loop-mediated isothermal amplification (LAMP) is the most popular technology for point-of-care testing applications due its rapid, sensitive and specific detection with simple instrumentation compared to PCR-based methods. Many systems for reading the results of LAMP amplifications exist, including real-time fluorescence detection using fluorophore-labelled probes attached to oligonucleotide sequences complementary to the target nucleic acid. This methodology allows the simultaneous detection of multiple targets (multiplexing) in one LAMP assay. A method for multiplexing LAMP is the amplification by release of quenching (DARQ) technique by using a 5'-quencher modified LAMP primer annealed to 3'-fluorophore-labelled acting as detection oligonucleotide. The main application of multiplex LAMP is the rapid and accurate diagnosis of infectious diseases, allowing differentiation of co-infecting pathogens in a single reaction. Schistosomiasis, caused among other species by Schistosoma mansoni and strongyloidiasis, caused by Strongyloides stercoralis, are the most common helminth-parasite infections worldwide with overlapping distribution areas and high possibility of coinfections in the human population. It would be of great interest to develop a duplex LAMP to detect both pathogens in the same reaction. In this study, we investigate the use of our two previously developed and well-stablished LAMP assays for S. mansoni and Strongyloides spp. DNA detection in a new duplex real-time eight-primer system based on a modified DARQ probe method that can be performed in a portable isothermal fluorimeter with minimal laboratory resources. We also applied a strategy to stabilize the duplexed DARQ-LAMP mixtures at room temperature for use as ready-to-use formats facilitating analysis in field settings as point-of-care diagnostics for schistosomiasis and strongyloidiasis.

A novel, non-neuronal acetylcholinesterase of schistosome parasites is essential for definitive host infection

Schistosomes are long-lived parasitic worms that infect >200 million people globally. The intravascular life stages are known to display acetylcholinesterase (AChE) activity internally as well as, somewhat surprisingly, on external tegumental membranes. Originally it was hypothesized that a single gene (SmAChE1 in Schistosoma mansoni) encoded both forms of the enzyme. Here, we demonstrate that a second gene, designated "S. mansoni tegumental acetylcholinesterase, SmTAChE", is responsible for surface, non-neuronal AChE activity. The SmTAChE protein is GPI-anchored and contains all essential amino acids necessary for function. AChE surface activity is significantly diminished following SmTAChE gene suppression using RNAi, but not following SmAChE1 gene suppression. Suppressing SmTAChE significantly impairs the ability of parasites to establish infection in mice, showing that SmTAChE performs an essential function for the worms in vivo. Living S. haematobium and S. japonicum parasites also display strong surface AChE activity, and we have cloned SmTAChE homologs from these two species. This work helps to clarify longstanding confusion regarding schistosome AChEs and paves the way for novel therapeutics for schistosomiasis.

A one-year unisexual Schistosoma mansoni infection causes pathologic organ alterations and persistent non-polarized T cell-mediated inflammation in mice

In exhibiting gonochorism and phenotypic sexual dimorphism, Schistosoma spp. are unique among trematodes. Only females mating with male schistosomes can produce the highly immunogenic parasite eggs which determine the clinical picture of the disease schistosomiasis. The strong immune-modulatory effect of the eggs masks the influence of the adult worms. To shed light on the complexity of the immune response triggered by adult worms of Schistosoma mansoni, we performed a long-term unisexual infection experiment in mice. We were able to demonstrate that both male and female schistosomes can survive unpaired for one year in the murine host. Furthermore, unisexual S. mansoni infection leads to pronounced inflammation of the liver characterized by a non-polarized Th1/Th2 immune response, regardless of worm sex.

Efficacy and safety of transjugular intrahepatic portosystemic shunt for the treatment of schistosomiasis-induced portal hypertension: a retrospective case series

BACKGROUND AND AIM

The aim of this study was to evaluate the efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) in the treatment of portal hypertension caused by schistosomiasis.

METHODS

This study included 43 patients with schistosomiasis-induced portal hypertension treated with TIPS in our institution from December 2015 to May 2021. The demographic, imaging, clinical and follow-up data of patients were recorded retrospectively to evaluate the efficacy and safety of the procedure.

RESULTS

All patients were successfully implanted with stents to establish shunt, and 90.7% of the patients were in good postoperative condition with no complications. After TIPS, the Yerdel grade of portal vein thrombosis decreased, and the portal pressure gradient decreased from 27.0 ± 4.9 mmHg to 11.3 ± 3.8 mmHg (P < 0.001). Bleeding was effectively controlled, with a postoperative rebleeding rate of 9.3%, which was an 87.9% reduction from the preoperative rate. The cumulative incidence of postoperative refractory ascites, shunt dysfunction, overt hepatic encephalopathy (OHE) and death were all similar to those of TIPS for nonschistosomiasis portal hypertension. There were no differences in liver and kidney function and blood coagulation indexes before and 3 months after TIPS. Albumin was identified as an independent risk factor for mortality after TIPS for schistosomal liver fibrosis.

CONCLUSION

TIPS can be used as a well-tolerated and effective treatment for schistosomiasis-induced portal hypertension, effectively reduce portal pressure gradient and improve portal vein thrombosis.

New challenges for the control of human schistosomiasis: The possible impact of wild rodents in Schistosoma mansoni transmission

Schistosomiasis is a neglected parasitic disease caused by digenean trematodes from the genus Schistosoma that affects millions of people worldwide. Despite efforts to control its transmission, this disease remains active within several endemic regions of Africa, Asia, and the Americas. In addition to the deficits in sanitation and educational structure, another major obstacle hindering the eradication of schistosomiasis is the ability of Schistosoma spp. to naturally infect multiple vertebrate hosts, particularly wild rodents. Due to climate change and other anthropogenic disturbances, contact between humans and wild animals has increased, and this has contributed to more frequent interactions between Schistosoma species that typically infect different hosts. This new transmission dynamic involving Schistosoma spp., humans, wild rodents, and livestock could potentially increase the frequency of Schistosoma hybridization and the establishment of new genotypes and strains. Although it is not currently possible to precisely measure how this biological phenomenon affects the epidemiology and morbidity of schistosomiasis, we speculate that these Schistosoma variants may negatively impact control strategies, treatment regimens, and disease burden in humans. In the present study, we discuss the natural infections of wild rodents with Schistosoma spp., the role of these animals as Schistosoma spp. reservoirs, and how they may select hybrids and strains of Schistosoma mansoni. We also discuss measures required to shed light on the actual role of the wild rodents Nectomys squamipes and Holochilus sciureus in the transmission and morbidity of schistosomiasis in Brazil.

Unusual and severe complications of acute schistosomiasis in travelers

Acute schistosomiasis (ASC) is a hypersensitivity reaction seen mostly in nonimmune travelers and manifests mainly with fever, urticaria, and respiratory symptoms. We describe unusual severe presentations of ASC in 3 patients, including hip-monoarthritis, peri-myocarditis, and optic neuritis. In all 3 patients, clinical symptoms appeared or worsened after praziquantel administration.

Think Outside the Box: A Rare Presentation of Schistosomiasis in the United States

Millions of people across the world are infected with schistosomiasis. But, the vast majority of them are asymptomatic. Milder symptoms can include headache, lethargy, and fever. In serious cases, ascites, hepatosplenomegaly, and death can occur. Schistosomiasis is a highly prevalent parasitic infection worldwide, mainly in tropical areas of Africa, Asia, and Latin America. We present a case of a 69-year-old female with notable travel history to the Philippines, who reported to the emergency department with a symptomatic presentation of chronic schistosomiasis with the involvement of biliary and pancreatic ducts.

Urinary Bladder Schistosomiasis Mimicking Neoplasm: A Case Report

Schistosomiasis is a neglected disease that is prevalent in tropical and subtropical areas. A 20-year-old woman presented to the emergency room with a history of right flank pain and lower abdominal discomfort for one day, which coincided with the onset of menses. The patient did not provide any history of premenstrual hematuria. The physical examination revealed right costovertebral angle tenderness and was otherwise unremarkable. The urinalysis demonstrated a mild increase in red and white blood cells and no ova or parasite. The blood test was normal, except for eosinophilia. A right pedunculated intraluminal urinary bladder mass was detected by the computerized axial tomographic scan and ultrasonography, and after the transurethral resection of the mass, the patient was diagnosed with urinary schistosomiasis. The patient received two doses of oral praziquantel of 1200 mg every 12 h for one day. The cure was confirmed with a one-month post-treatment follow-up that revealed a normal urine microscope and eosinophil count. The S. haematobium infection should be evaluated as a possible cause of urinary bladder lesion in those who have travelled or lived in endemic areas.

Urogenital schistosomiasis prevalence and diagnostic performance of urine filtration and urinalysis reagent strip in schoolchildren, Ethiopia

Background

Urogenital schistosomiasis has been known to be endemic in several lowland areas of Ethiopia. It is caused by Schistosoma haematobium and causes considerable public health problems to schoolchildren. Ethiopia, after mapping the distribution of the disease (2013 to 2015), launched school-based mass deworming program to treat schoolchildren for schistosomiasis and soil-transmitted helminthiasis (STH) across the country since 2015. However, there is no recent information about the prevalence of the disease among schoolchildren in the current study areas. Diagnostic performance of urine filtration method and urinalysis reagent strip is also lacking. Therefore, this study aimed to determine the prevalence of urogenital schistosomiasis in schoolchildren, and to evaluate diagnostic performance of urine filtration and urinalysis reagent strip in Amibara, Kurmuk and Abobo districts, Ethiopia.

Methods

Across-sectional study was conducted involving 1,171 schoolchildren in Abobo, Amibara and Kurmuk districts from October, 2020 to January, 2021. The study participants were selected using random sampling technique. From each study participant, 10 ml urine samples were collected and examined using urine filtration method and urinalysis reagent strip. Data obtained from the survey were entered into Microsoft Excel 2010 and analysed with SPSS version 20.0. Data was summarized using descriptive statistics. Chi-square, bivariate and multivariable logistic regression and Pearson correlation test were used to measure associations between urogenital schistosomiasis, age, sex and haematuria. Odds ratio was used to measure strengths of association between variables. Agreement between urine filtration method and urinalysis reagent strip was determined using Kappa statistics. P-value < 0.05 at 95% CI was considered as statistically significant.

Results

Among the 1,171 urine samples from schoolchildren examined by urine filtration method, 143 (12.2%) were S.haematobium egg positive. Out of 143 positive children 126(88.1%) were lightly infected and 17 (11.9%) were heavily infected. Among the total of 1,171 urine samples tested by dipstick, 264(22.5%) were positive for haematuria. Prevalence of urogenital schistosomiasis by both urine filtration and urinalysis reagent strip method was higher in Abobo than Hassoba (Amibara) and Kurmuk (P< 0.001). The number of egg counts (intensity of infections) were significantly correlated with intensity of haematuria (r = 0.6, P < 0.001). Egg-positive children had significantly higher risk of having haematuria compared to S. haematobium egg negative children (OR; 6.96; 95%CI: 4.98, 8.940). Compared to urine filtration method, the sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV) of urinalysis reagent strip were 99.3%, 88.1%, 53.8% and 99.8%, respectively. Furthermore, its positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 8.34 and 0.008, respectively. The accuracy index and diagnostic odds ratio (DOR) of reagent strip were 0.89 and 1054, respectively. The agreement level between urine filtration methods and urinalysis reagent strip for detecting urogenital schistosomiasis was substantial (Kappa = 0.64).

Conclusion

This study showed that urogenital schistosomiasis was prevalent in schoolchildren in Abobo, Hassoba and Kurmuk districts. Urogenital schistosomiasis prevalence in Hassoba-bure and Kurmuk falls under low category whereas moderate in Abobo and is almost four times compared to Kurmuk and Hassoba-bure. Chemotherapy is needed in schoolchildren in such endemic areas and other measures like access to safe water, improved sanitation, hygiene, and health education should be implemented to control and prevent schistosomiasis effectively. The sensitivity, specificity, positive and negative predictive values of urinalysis reagent strip were higher and could serve as alternative for mass screening of urogenital schistosomiasis, for surveillance and evaluation of schistosomiasis intervention programs.

Design of live-attenuated animal vaccines based on pseudorabies virus platform

Pseudorabies virus (PRV) is a double-stranded DNA virus with a genome approximating 150 kb in size. PRV contains many non-essential genes that can be replaced with genes encoding heterogenous antigens without affecting viral propagation. With the ability to induce cellular, humoral and mucosal immune responses in the host, PRV is considered to be an ideal and potential live vector for generation of animal vaccines. In this review, we summarize the advances in attenuated recombinant PRVs and design of PRV-based live vaccines as well as the challenge of vaccine application.

Human tumor necrosis factor alpha affects the egg-laying dynamics and glucose metabolism of Schistosoma mansoni adult worms in vitro

Several studies have described the effects of human tumor necrosis factor alpha (hTNF-α) on Schistosoma mansoni. hTNF-α affects the worm’s development, metabolism, egg-laying, gene expression and protein phosphorylation. The available data on the influence of hTNF-α on egg-laying in S. mansoni are controversial, but understanding the mechanism of egg-laying regulation in this species is essential in combating schistosomiasis. We characterized the effects of in vitro treatment of S. mansoni adult worms with different doses of hTNF-α (5, 20 and 40 ng/ml) for 5 days. We explored the effects on egg-laying rate, glucose levels, ATP metabolism, and messenger RNA (mRNA) expression levels of lactate dehydrogenase, glucose transporters and the parasite gene which acts as an hTNF-α receptor, SmTNFR. hTNF-α influenced egg-laying in a time- and dose-dependent manner: at a dose of 40 ng/ml, egg-laying increased on day 2 and decreased on days 3 and 4; at 20 ng/ml, egg-laying decreased on day 3; while at 5 ng/ml, egg-laying decreased on day 4. The total number of eggs produced was not affected by the different treatments, but the egg-laying dynamics were: the median egg-laying time decreased significantly with treatment, and egg developmental stages and size were also affected. At 5 and 20 ng/ml hTNF-α, lactate production diminished on day 3 up to day 5, while glucose uptake increased on day 5. At 40 ng/ml, glucose uptake diminished on day 1 up to day 3, while ATP accumulation was detected on day 5. No significant changes in mRNA expression were detected in any of the treatments. We found that crosstalk involving hTNF-α and parasite signaling plays a role in the fine-scale regulation of the worm’s metabolism and physiology, and points to new strategies for disease control.

Real-time and automated monitoring of antischistosomal drug activity profiles for screening of compound libraries

Schistosomiasis is a neglected tropical disease that affects over 200 million people annually. As the antischistosomal drug pipeline is currently empty, repurposing of compound libraries has become a source for accelerating drug development, which demands the implementation of high-throughput and efficient screening strategies. Here, we present a parallelized impedance-based platform for continuous and automated viability evaluation of Schistosoma mansoni schistosomula in 128 microwells during 72 h to identify antischistosomal hits in vitro. By initially screening 57 repurposed compounds against larvae, five drugs are identified, which reduce parasite viability by more than 70%. The activity profiles of the selected drugs are then investigated via real-time dose-response monitoring, and four compounds reveal high potency and rapid action, which renders them suitable candidates for follow-up tests against adult parasites. The study shows that our device is a reliable tool for real-time drug screening analysis of libraries to identify new promising therapeutics against schistosomiasis.

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Scalable, plastic microwell chip with integrated platinum electrodes

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Automated impedance-based recording of 128 microwell units in parallel

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Continuous monitoring of in vitro drug library efficacy on schistosomula for 72 h

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Identification of four fast-acting antischistosomal drugs for in vivo testing

Neutrophils and schistosomiasis: a missing piece in pathology

Schistosomiasis is a chronic human parasitic disease that causes serious health problems worldwide. The disease-associated liver pathology is one of the hallmarks of infections by S. mansoni and S. japonicum, and is accountable for the debilitating condition found in infected patients. In the past few years, investigative studies have highlighted the key role played by neutrophils and the influence of inflammasome signaling pathway in different pathological conditions. However, it is noteworthy that the study of inflammasome activation in neutrophils has been overlooked by reports concerning macrophages and monocytes. This interplay between neutrophils and inflammasomes is much more poorly investigated during schistosomiasis. Herein we reviewed the role of neutrophils during schistosomiasis and addressed the potential connection between these cells and inflammasome activation in this context.

Antischistosomal tetrahydro-γ-carboline sulfonamides

We discovered tetrahydro-γ-carboline sulfonamides as a new antischistosomal chemotype. The aryl sulfonamide and tetrahydro-γ-carboline substructures were required for high antischistosomal activity. Increasing polarity improved solubility and metabolic stability but decreased antischistosomal activity. We identified two compounds with IC₅₀ values <5 µM against ex vivo Schistosoma mansoni.

Characterisation of tetraspanins from Schistosoma haematobium and evaluation of their potential as novel diagnostic markers

Schistosoma haematobium is the leading cause of urogenital schistosomiasis and it is recognised as a class 1 carcinogen due to the robust association of infection with bladder cancer. In schistosomes, tetraspanins (TSPs) are abundantly present in different parasite proteomes and could be potential diagnostic candidates due to their accessibility to the host immune system. The large extracellular loops of six TSPs from the secretome (including the soluble excretory/secretory products, tegument and extracellular vesicles) of S. haematobium (Sh-TSP-2, Sh-TSP-4, Sh-TSP-5, Sh-TSP-6, Sh-TSP-18 and Sh-TSP-23) were expressed in a bacterial expression system and polyclonal antibodies were raised to the recombinant proteins to confirm the anatomical sites of expression within the parasite. Sh-TSP-2, and Sh-TSP-18 were identified on the tegument, whereas Sh-TSP-4, Sh-TSP-5, Sh-TSP-6 and Sh-TSP-23 were identified both on the tegument and internal tissues of adult parasites. The mRNAs encoding these TSPs were differentially expressed throughout all schistosome developmental stages tested. The potential diagnostic value of three of these Sh-TSPs was assessed using the urine of individuals (stratified by infection intensity) from an endemic area of Zimbabwe. The three Sh-TSPs were the targets of urine IgG responses in all cohorts, including individuals with very low levels of infection (those positive for circulating anodic antigen but negative for eggs by microscopy). This study provides new antigen candidates to immunologically diagnose S. haematobium infection, and the work presented here provides compelling evidence for the use of a biomarker signature to enhance the diagnostic capability of these tetraspanins.

Schistosoma haematobium, the leading cause of urogenital schistosomiasis, affects millions of people worldwide. Infection with this parasite is associated with different clinical complications such as squamous cell carcinoma and genital malignancy in women. Despite its importance, there is a lack of sensitive and specific diagnostics that support control and elimination initiatives against this devastating disease. Herein, we have characterised six molecules belonging to the tetraspanin family of membrane proteins, providing details about their relative expression during parasite’s development and their localization in adult forms of S. haematobium. Furthermore, we have characterised the antibody responses against three of these molecules in urine from infected human subjects from an endemic area, providing compelling evidence for the use of these molecules to diagnose urogenital schistosomiasis.

Transmission Dynamics of Schistosoma haematobium among School-Aged Children: A Cohort Study on Prevalence, Reinfection and Incidence after Mass Drug Administration in the White Nile State of Sudan

The reinfection rate of schistosomiasis after mass drug administration (MDA) has not been documented in Sudan. We aimed to explore the transmission dynamics of urogenital schistosomiasis after MDA, targeting school-aged children in the White Nile State of Sudan, assessing the prevalence, reinfection rate, and incidence. A single dose of praziquantel (40 mg/kg) was administered to 1951 students in five primary schools from January to February 2018 immediately after a baseline survey, and follow-up surveys were performed at 2 weeks and 6 months after treatment. We examined Schistosoma haematobium eggs by centrifugation methods. The overall reinfection rate at 6 months after treatment was 9.8% (95% confidence interval: 0.5-17.4%). By school, the reinfection rate was highest in the Al Hidaib school, whose prevalence was highest at baseline. The reinfection rate was significantly higher in high-infection areas than low-infection areas (p = 0.02). Of the prevalence at 6 months in high-infection areas, 41% of cases were due to reinfection. MDA interventions are decided upon and undertaken at the district level. A more targeted treatment strategy should be developed with a particular focus on tracking high-risk groups, even within a school or a community.

Pediatric non-cirrhotic portal hypertension: Endoscopic outcome and perspectives from developing nations

Non-cirrhotic portal hypertension (NCPH) forms an important subset of portal hypertension in children. Variceal bleed and splenomegaly are their predominant presentation. Laboratory features show cytopenias (hypersplenism) and preserved hepatic synthetic functions. Repeated sessions of endoscopic variceal ligation or endoscopic sclerotherapy eradicate esophageal varices in almost all cases. After variceal eradication, there is an increased risk of other complications like secondary gastric varices, cholangiopathy, colopathy, growth failure, especially in extra-hepatic portal vein obstruction (EHPVO). Massive splenomegaly-related pain and early satiety cause poor quality of life (QoL). Meso-Rex bypass is the definitive therapy when the procedure is anatomically feasible in EHPVO. Other portosystemic shunt surgeries with splenectomy are indicated when patients present late and spleen-related issues predominate. Shunt surgeries prevent rebleed, improve growth and QoL. Non-cirrhotic portal fibrosis (NCPF) is a less common cause of portal hypertension in children in developing nations. Presentation in the second decade, massive splenomegaly and patent portal vein are discriminating features of NCPF. Shunt surgery is required in severe cases when endotherapy is insufficient for the varices. Congenital hepatic fibrosis (CHF) presents with firm palpable liver and splenomegaly. Ductal plate malformation forms the histological hallmark of CHF. CHF is commonly associated with Caroli’s disease, renal cysts, and syndromes associated with neurological defects. Isolated CHF has a favourable prognosis requiring endotherapy. Liver transplantation is required when there is decompensation or recurrent cholangitis, especially in Caroli’s syndrome. Combined liver-kidney transplantation is indicated when both liver and renal issues are present.

Schistosome-Associated Pulmonary Arterial Hypertension: A Review Emphasizing Pathogenesis

Schistosomiasis, especially due to Schistosoma mansoni, is a well-recognized cause of pulmonary arterial hypertension (PAH). The high prevalence of this helminthiasis makes schistosome-related PAH (Sch-PAH) one of the most common causes of this disorder worldwide. The pathogenic mechanisms underlying Sch-PAH remain largely unknown. Available evidence suggests that schistosome eggs reach the lung via portocaval shunts formed as a consequence of portal hypertension due to hepatosplenic schistosomiasis. Once deposited into the lungs, the eggs elicit an immune response resulting in periovular granuloma formation. Immune mediators drive transforming growth factor-β (TGF-β) release, which gives rise to pulmonary vascular inflammation with subsequent remodeling and development of angiomatoid and plexiform lesions. These mechanisms elicited by the eggs seem to become autonomous and the vascular lesions progress independently of the antigen. Portopulmonary hypertension, which pathogenesis is still uncertain, may also play a role in the genesis of Sch-PAH. Recently, there have been substantial advances in the diagnosis and treatment of PAH, but it remains a difficult condition to recognize and manage, and patients still die prematurely from right-heart failure. Echocardiography is used for screening, and the formal diagnosis requires right-heart catheterization. The experience in treating Sch-PAH is largely limited to the phosphodiesterase type 5 inhibitors, with evidence suggesting that these vasodilators improve symptoms and may also improve survival. Considering the great deal of uncertainty about Sch-PAH pathogenesis, course, and treatment, the aim of this review is to summarize current knowledge on this condition emphasizing its pathogenesis.

Preparation and In Vitro/In Vivo Evaluation of Orally Disintegrating/Modified-Release Praziquantel Tablets

This study was designed to develop orally disintegrating/sustained-release praziquantel (PZQ) tablets using the hot-melt extrusion (HME) technique and direct compression, and subsequently evaluate their release in in vitro and in vivo pharmacokinetics. For the extrusion process, hypromellose acetate succinate (HPMCAS)-LG was the carrier of pure PZQ, with a standard screw configuration used at an extrusion temperature of 140 °C and a screw rotation speed of 100 rpm. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) and Fourier-transform infrared spectroscopy (FTIR) were performed to characterize the extrudate. Orally disintegrating/sustained-release praziquantel tablets (PZQ ODSRTs) were prepared by direct compression after appropriate excipients were blended with the extrudate. The release amount was 5.10% in pH 1.0 hydrochloric acid at 2 h and over 90% in phosphoric acid buffer at 45 min, indicating the enteric-coating character of PZQ ODSRTs. Compared with the pharmacokinetics of marketed PZQ tablets (Aipuruike^®) in dogs, the times to peak (T_max), elimination half-life (t_1/2λ) and mean residence time (MRT) were extended in PZQ ODSRTs, and the relative bioavailability of PZQ ODSRTs was up to 184.48% of that of Aipuruike^®. This study suggested that PZQ ODSRTs may have potential for the clinical treatment of parasitosis.

Granulocytic myeloid-derived suppressor cells inhibit T follicular helper cells during experimental Schistosoma japonicum infection

Background

CD4⁺ T helper (Th) cells play critical roles in both host humoral and cellular immunity against parasitic infection and in the immunopathology of schistosomiasis. T follicular helper (Tfh) cells are a specialized subset of Th cells involved in immunity against infectious diseases. However, the role of Tfh cells in schistosome infection is not fully understood. In this study, the dynamics and roles of Tfh cell regulation were examined. We demonstrated that granulocytic myeloid-derived suppressor cells (G-MDSC) can suppress the proliferation of Tfh cells.

Methods

The levels of Tfh cells and two other Th cells (Th1, Th2) were quantitated at different Schistosoma japonicum infection times (0,3, 5, 8, 13 weeks) using flow cytometry. The proliferation of Tfh cells stimulated by soluble egg antigen (SEA) and soluble worm antigen (SWA) in vivo and in vitro were analyzed. Tfh cells were co-cultured with MDSC to detect the proliferation of Tfh cells labelled by 5(6)-carboxyfluorescein diacetate N-succinimidyl ester. We dynamically monitored the expression of programmed cell death protein 1 (PD-1) on the surface of Tfh cells and programmed cell death ligand 1 (PD-L1) on the surface of MDSC at different infection times (0, 3, 5, 8 weeks). Naïve CD4⁺ T cells (in Tfh cell differentiation) were co-cultured with G-MDSC or monocytic MDSC in the presence, or in the absence, of PD-L1 blocking antibody.

Results

The proportion of Tfh cells among CD4⁺ T cells increased gradually with time of S. japonicum infection, reaching a peak at 8 weeks, after which it decreased gradually. Both SEA and SWA caused an increase in Tfh cells in vitro and in vivo. It was found that MDSC can suppress the proliferation of Tfh cells. The expression of PD-1 on Tfh cells and PD-L1 from MDSC cells increased with prolongation of the infection cycle. G-MDSC might regulate Tfh cells through the PD-1/PD-L1 pathway.

Conclusions

The reported study not only reveals the dynamics of Tfh cell regulation during S. japonicum infection, but also provides evidence that G-MDSC may regulate Tfh cells by PD-1/PD-L1. This study provides strong evidence for the important role of Tfh cells in the immune response to S. japonicum infection.

Graphical abstract

Medical Imaging in the Diagnosis of Schistosomiasis: A Review

Schistosomiasis is one of the most important parasitic diseases and it is endemic in tropical and subtropical areas. Clinical and laboratory data are fundamental for the diagnosis of schistosomiasis, but diagnostic imaging techniques such as x-rays, ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography/computed tomography (PET/CT) may be helpful in the evaluation of disease severity and complications. In this context, the aim of this review is to explore the actual role of diagnostic imaging in the diagnosis of schistosomiasis, underlining advantages and drawbacks providing information about the utilization of diagnostic imaging techniques in this context. Furthermore, we aim to provide a useful guide regarding imaging features of schistosomiasis for radiology and nuclear medicine physicians of non-endemic countries: in fact, in the last years non-endemic countries have experienced important flows of migrants from endemic areas, therefore it is not uncommon to face cases of this disease in daily practice.

Evaluation of a urogenital schistosomiasis behavioural intervention among students from rural schools in Unguja and Pemba islands, Zanzibar

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Children self-reported changes in urogenital schistosomiasis risk taking behaviours.

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Children self-reported an increase in swallowing anthelmintic drugs during MDA.

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Rebranding the concept of “worm” to “blood fluke” created a critical perceived health threat.

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The Health Belief Model was a viable foundation for the behavioural intervention.

Urogenital schistosomiasis is a common experience among children in Zanzibar. There is a paucity of behavioural science-based, health education and behaviour change (HEBC) interventions for school-aged children, those at greatest risk for urogenital schistosomiasis. We assessed the influence of a HEBC intervention, guided by the Health Belief model, among rural schoolchildren on Pemba and Unguja islands in Zanzibar, Tanzania. From 2012 to 2016, a cluster-randomized trial to assess three different interventions against urogenital schistosomiasis was conducted in 90 schools and shehias across Zanzibar. The HEBC intervention was implemented in 15 schools per island. In 2017, at the trial conclusion, we administered written questionnaires to schoolchildren from 4 HEBC intervention schools and 4 not HEBC exposed schools on each island, respectively. Responses were compared between students that were exposed or not exposed to the HEBC intervention using a Fisher's exact test. A total of 1451 students, 708 from intervention and 743 from non-intervention schools completed the questionnaire. Noting some between island differences, students who had received the HEBC interventions reported significant improvements in knowledge about Schistosoma haematobium transmission and personal risk, strategies for schistosomiasis prevention, and self-reported changes in risk behaviours: stopped washing laundry/dishes 49.4% (350/708) versus 5.8% (43/743), stopped bathing in streams/ponds 49.4% (350/708) versus 4.2% (31/743), and stopped playing in streams/ponds 40.8% (289/708) versus 10.8% (80/743). HEBC exposed children also reported a significant increase in swallowing tablets during mass drug administration (MDA) campaigns (when they had not before) 30.2% (214/708) versus 4.6% (34/743). The school based HEBC interventions were associated with desirable positive behaviour change among students. Data suggest that scaling up HEBC interventions to all schools in high-risk areas, augmented with bi-annual MDA, can help to reduce prevalence of urogenital schistosomiasis in Zanzibar, strengthening the possibility for future disease elimination.

Detection of Urinary Antibodies and Its Application in Epidemiological Studies for Parasitic Diseases

For epidemiological studies of infectious diseases, pathogen-specific antibody levels in an area give us essential and appropriate information. The antibodies against pathogens are usually detected in blood, the drawing of which inconveniences people. Collection of blood increases the risk of accidental infections through blood, and it is difficult to obtain the participation of the target populations, especially the younger generation. On the other hand, urine samples, which contain a high enough level of antibodies for ELISA, can be harmlessly and easily collected and therefore have been used for epidemiological studies for diseases. The antibody examination of urine has been used for the epidemiology of parasitic diseases with a high sensitivity and specificity of serum samples. In this paper, we reviewed antibody assays with urine for seven parasitic diseases that urine diagnostic methods have reported in the past, and these are important infections included in NTDs, caused, for example, by Leishmania donovani, Wuchereria bancrofti, Schistosoma japonicum, Paragonimus westermani, Echinococcus granulosus, Echinococcus multilocularis, Strongyloides stercoralis, and Opisthorchis viverrini. The easy and safe urine surveillance system might be an admirable tool for future epidemiological studies for infectious diseases.

Urological Emergencies and Diseases in Wilderness Expeditions

When considering medical emergencies that might affect an expedition, urologic emergencies are typically not included. However, the reality is that manageable and prevalent urologic disease processes can pose significant challenges for the wilderness medicine physician and warrant consideration. The purpose of this review is to identify and discuss the most commonly encountered urologic emergencies and diseases in the wilderness setting and to prepare the expedition medicine physician for management of these urgent conditions. A PubMed and Internet search for urologic emergencies and diseases in wilderness conditions was conducted. We also searched bibliographies for useful supplemental literature and material from leading mountain medicine and wilderness medicine societies as well as population-based studies for common urologic diseases. Urologic emergencies and diseases on expeditions and in wilderness conditions have been reported primarily with retrospective case series and case reports. The most commonly reported urologic emergencies in this setting include urologic trauma, renal calculi, and urinary retention. Parasitic infections in the urinary tract also have been reported to cause urinary symptoms and urinary retention in wilderness conditions. Although urologic diseases in such conditions are uncommon, significant morbidity and even potentially life-threatening sequelae to urologic emergencies were found to occur. Major genitourinary emergencies in expedition medicine are uncommon but involve both potentially manageable urgent conditions and serious life-threatening conditions best treated with urgent stabilization and occasionally medical evacuation. The opportunity exists for increased awareness for management strategies for urologic conditions in the often remote or extreme environments of an expedition.

Argon laser photocoagulation for treatment of presumed trematode-induced granulomatous anterior uveitis in children

Background/Aims

To assess the safety and efficacy of argon laser photocoagulation as a new modality for the treatment of presumed trematode-induced granulomatous anterior uveitis (PTGAU) in children.

Methods

Forty-eight eyes of 48 children with PTGAU with pearl-like nodule(s) in the anterior chamber were included in this prospective non-randomised controlled clinical trial. The patients were divided into two groups: those in Group A (23 eyes) were treated with one session of argon laser applied to the anterior chamber nodules and those in Group B (25 eyes) received medical treatment in the form of topical steroid and cycloplegic eye drops with trans-septal triamcinolone injections. All cases were followed up for 3 months with measurement of visual acuity (VA), assessment of the anterior chamber reaction and measurement of the pearl-like nodule size.

Results

In Group A, 22 eyes (95.65%) showed regression of the pearl-like nodules with resolution of the anterior chamber reaction (flare and cells) and improvement in visual acuity from 0.52±0.12 to 0.06±0.08 logMAR (p<0.001). Such improvement was maintained within the 3-month follow-up period. In Group B, 23 eyes (92%) showed initial regression of the granulomas, which was maintained in only 14 eyes (56%),with nine eyes experiencing recurrence after 3 months of follow-up.

Conclusion

Argon laser photocoagulation is a safe and effective novel treatment for PTGAU with pearl-like nodules in the anterior chamber in children. Larger studies with longer follow-up periods are needed to confirm these results.

Infection-Associated Thymic Atrophy

The thymus is a vital organ of the immune system that plays an essential role in thymocyte development and maturation. Thymic atrophy occurs with age (physiological thymic atrophy) or as a result of viral, bacterial, parasitic or fungal infection (pathological thymic atrophy). Thymic atrophy directly results in loss of thymocytes and/or destruction of the thymic architecture, and indirectly leads to a decrease in naïve T cells and limited T cell receptor diversity. Thus, it is important to recognize the causes and mechanisms that induce thymic atrophy. In this review, we highlight current progress in infection-associated pathogenic thymic atrophy and discuss its possible mechanisms. In addition, we discuss whether extracellular vesicles/exosomes could be potential carriers of pathogenic substances to the thymus, and potential drugs for the treatment of thymic atrophy. Having acknowledged that most current research is limited to serological aspects, we look forward to the possibility of extending future work regarding the impact of neural modulation on thymic atrophy.

Comparison of point-of-care test and enzyme-linked immunosorbent assay for detection of immunoglobulin G antibodies in the diagnosis of human schistosomiasis japonica

OBJECTIVE

Schistosomiasis japonica is an important helminthic disease in Asia. Sensitive and accurate diagnostic tools are indispensable for clinical diagnosis, screening infection and monitoring its control. In this study, we developed an immunochromatographic test (Sj-ICT) to detect anti-Schistosoma japonicum immunoglobulin G antibodies in human sera.

METHODS

Somatic extract from adult S. japonicum was used as an antigen. The Sj-ICT was developed and optimized as a point-of-care test. All 214 human serum samples were evaluated for diagnostic usefulness and comparison with an enzyme-linked immunosorbent assay (ELISA).

RESULTS

The diagnostic sensitivity, specificity, positive and negative predictive values, and accuracy of the Sj-ICT were 90.8%, 87.9%, 86.4%, 91.9% and 89.3%, respectively. For ELISA the values were respectively 91.8%, 87.9%, 86.5%, 92.7% and 89.7%. The concordance between both methods was 86.4 % (Cohen's kappa value = 0.729).

CONCLUSIONS

The immunochromatographic test kit developed can support clinical diagnosis and large-scale surveys in endemic areas without requiring additional facilities or ancillary supplies.

A Novel Treatment of Schistosomiasis: Nano-Calcium Silicate Incorporating 5% Copper Oxide

Purpose: Praziquantel (PZQ) is a well-known drug accredited by the World Health Organization (WHO) for the treatment of schistosomiasis. It shows poor efficiency in patients during the earliest infection phases. Therefore, the search for new alternative drugs was the intention of many researchers. Methods: In the current study, the effect of different concentrations (ranging from 0.07-10 μg∕mL) of calcium silicate (CS) containing 5% copper oxide [CS-5%CuO] on golden hamster infected by Schistosoma mansoni and Schistosoma haematobium (Egyptian strains) was evaluated in both in vitro and in vivo. To the best of our knowledge, this is a novel study in investigating the efficiency of CS-5%CuO against both strains of schistosomes. The worms of S. mansoni and S. haematobium were tested in RPMI-1640 medium in vitro. Results: The results declare that CS-5% CuO exhibited excellent anti-schistosomal activities on both in vitro and in vivo experiments for both Egyptians Schistosoma strains. The most potential effect of the CS-5% CuO was exhibited after 6 h by 10 μg∕mL with significant activity of (P value = 0.001). Conclusion: Therefore, CS-5%CuO may become an innovative treatment for the schistosomiasis.

Extracellular Vesicles: Schistosomal Long-Range Precise Weapon to Manipulate the Immune Response

Schistosomiasis (Bilharziasis), a neglected tropical disease that affects more than 240 million people around the world, is caused by infection with the helminth parasite Schistosoma. As part of their secretome, schistosomes release extracellular vesicles (EVs) that modulate the host immune response. The EV-harbored miRNAs upregulate the innate immune response of the M1 pathway and downregulate the differentiation toward the adaptive Th2 immunity. A schistosomal egg-derived miRNA increases the percentage of regulatory T cells. This schistosomal-inducible immunoediting process generates ultimately a parasitic friendly environment that is applied carefully as restrained Th2 response is crucial for the host survival and successful excretion of the eggs. Evidence indicates a selective targeting of schistosomal EVs, however, the underlying mechanisms are unclear yet. The effects of the schistosomes on the host immune system is in accordance with the hygiene hypothesis, attributing the dramatic increase in recent decades in allergy and other diseases associated with imbalanced immune response, to the reduced exposure to infectious agents that co-evolved with humans during evolution. Deciphering the bioactive cargo, function, and selective targeting of the parasite-secreted EVs may facilitate the development of novel tools for diagnostics and delivered therapy to schistosomiasis, as well as to immune-associated disorders.

Phenotypic Characterization of CD4+ T Lymphocytes in Periportal Fibrosis Secondary to Schistosomiasis

Schistosomiasis is a parasitic disease that affects about 166 million people around the world. It is estimated that 5%-10% of individuals with schistosomiasis develop severe forms of the disease, which are characterized by pulmonary hypertension, ascites, periportal fibrosis, and other significant complications. The chronic phase of the disease is associated with a Th2 type immune response, but evidence also suggests there are roles for Th1 and Th17 in the development of severe disease. The aim of this study was to evaluate the CD4+ T lymphocyte profile of patients with different degrees of periportal fibrosis secondary to schistosomiasis. These individuals had been treated for schistosomiasis, but since they live in a S. mansoni endemic area, they are at risk of reinfection. They were evaluated in relation to the degree of periportal fibrosis and classified into three groups: without fibrosis or with incipient fibrosis (WF/IFNE), n=12, possible periportal fibrosis/periportal fibrosis, n=13, and advanced periportal fibrosis/advanced periportal fibrosis with portal hypertension, n=4. We observed in the group without fibrosis a balance between the low expression of Th2 cytokines and high expression of T reg cells. As has already been described in the literature, we found an increase of the Th2 cytokines IL-4, IL-5, and IL-13 in the group with periportal fibrosis. In addition, this group showed higher expression of IL-17 and IL-10 but lower IL-10/IL-13 ratio than patients in the WF/IFNE group. Cells from individuals who present any level of fibrosis expressed more TGF-β compared to the WF/IFNE group and a positive correlation with left lobe enlargement and portal vein wall thickness. There was a negative correlation between IL-17 and the thickness of the portal vein wall, but more studies are necessary in order to explore the possible protective role of this cytokine. Despite the fibrosis group having presented a higher expression of pro-fibrotic molecules compared to WF/IFNE patients, it seems there is a regulation through IL-10 and T reg cells that is able to maintain the low morbidity of this group.

Structure determination and analyses of the GAPDH from the parasite Schistosoma mansoni, the first one from a platyhelminth

The enzyme Glyceraldehyde-3-Phosphate Dehydrogenase from Schistosoma mansoni (SmGAPDH) is characterized as a therapeutical target for schistosomiasis. In this context, we report here the experimental structure, structural analyses and comparisons of SmGAPDH, the first one from a Platyhelminth. The enzyme was expressed, purified and assayed for crystallization, what allowed the obtainment of crystals of sufficient quality to collect X-ray diffraction data up to 2.51 Å resolution. SmGAPDH is the only GAPDH to present the sequence NNR (its residues 114-116) which leads to (especially R116) a hydrogen bond network that possibly reflects on the flexibility of residues to interact with the adenine part of NAD⁺, speculated to be important for differential drug design.

Argon Laser Photocoagulation for Treatment of Presumed Trematode-induced Granulomatous Anterior Uveitis in Children.. [DOI: 10.1101/2020.12.30.20248850]

Background/Aims

To assess the safety and efficacy of argon laser photocoagulation as a new modality for the treatment of presumed trematode-induced granulomatous anterior uveitis (PTGAU) in children.

Methods

Forty-eight eyes of 48 children with PTGAU with pearl-like nodule(s) in the anterior chamber were included in this prospective non- randomised controlled clinical trial. Patients were divided into two groups: group A (23 eyes) was treated with one session of argon laser applied to the anterior chamber nodules, and group B (25 eyes) received medical treatment in the form of topical steroid and cycloplegic eye drops with trans-septal triamcinolone injection.All cases were followed up for 3 monthswith measurement of VA, assessment of anterior chamber reaction, and size of the pearl-like nodules.

Results

In group A, 22 eyes (95.65%) showed regression of the pearl- like nodules with resolution of the anterior chamber reaction (flare and cells) and improvement in visual acuity from 0.52±0.12 to 0.06 ± 0.08logMAR (p value <0.001). Such improvement was maintained within the 3-month follow-up period. In group B, 23 eyes (92%) showed initial regression of the granulomas,whichwas maintained in only 14 eyes (56%),with 9 eyes experiencing recurrence after 3 months of follow-up.

Conclusion

Argon laser photocoagulation is a safe and effective novel treatment for PTGAU with pearl-like nodules in the anterior chamber in children. Larger studies with longer follow-up periods are needed to confirm these results.

PRECIS

Argon laser photocoagulation is a novel non-invasive line of treatment that can be added to the armamentarium for presumed trematode-induced granulomatous anterior uveitis in children.

The cost-effectiveness of schistosomiasis screening and treatment among recently resettled refugees to Canada: an economic evaluation

BACKGROUND

Many refugees and asylum seekers from countries where schistosomiasis is endemic are infected with the Schistosoma parasite when they arrive in Canada. We assessed, from a systemic perspective, which of the following management strategies by health care providers is cost-effective: testing for schistosomiasis and treating if the individual is infected, treating presumptively or waiting for symptoms to emerge.

METHODS

We constructed a decision-tree model to examine the cost-effectiveness of 3 management strategies: watchful waiting, screening and treatment, and presumptive treatment. We obtained data for the model from the literature and other sources, to predict deaths and chronic complications caused by schistosomiasis, as well as costs and net monetary benefit.

RESULTS

Presumptive treatment was cost-saving if the prevalence of schistosomiasis in the target population was greater than 2.1%. In our baseline analysis, presumptive treatment was associated with an increase of 0.156 quality-adjusted life years and a cost saving of $405 per person, compared with watchful waiting. It was also more effective and less costly than screening and treatment.

INTERPRETATION

Among recently resettled refugees and asylum claimants in Canada, from countries where schistosomiasis is endemic, presumptive treatment was predicted to be less costly and more effective than watchful waiting or screening and treatment. Our results support a revision of the current Canadian recommendations.